ToddlerBot 2.0 parts list

Research humanoid about toddler size, built from Dynamixel servos and printed parts, with full RL and teleoperation software.

Humanoidsadvanced by Stanford (Haochen Shi and the TML lab)

Total parts cost: $5,730 to $7,760 (cheapest listed sellers add up to about $5,939)

Low end is the official BOM essentials total for the recommended 2XC version ($5,727.94); high end is the stronger 2XM version ($7,293.56) plus today's higher Jetson price ($1,399 vs $955 in the BOM). Excludes the custom power PCB (JLCPCB), tools (about $1,976 in the BOM, mostly a Bambu printer and soldering kit) and the optional teleop arms.

Exploded view

Tap any part to see where to buy it. Diagram is schematic, not to scale.

Every part you need

Part	Qty	Spec	Where to buy
DYNAMIXEL 2XC430-W250-T arm and hip servos (dual axis)	2	2XC version qty 2; 2XM version qty 6 Two-axis servo packs that save space at the shoulders and hips.	ROBOTIS: $298.89
DYNAMIXEL 2XL430-W250-T dual axis servos (2XC version)	6	2XC version only (2XM uses 2XC430 instead); BOM $149.39 Cheaper two-axis packs; the maintainer says 2XL works if budget is tight.	ROBOTIS: $149.39
DYNAMIXEL XC330-T288-T wrist, neck and small joints	6	Plus 2 more for the optional parallel gripper Small, light servos for low-load joints.	ROBOTIS: $103.39
DYNAMIXEL XC430-T240BB-T mid-load joints	4	Same qty in both versions Mid-torque joints where XC330s are too weak.	ROBOTIS: $137.89
DYNAMIXEL XM430-W210-T leg servos	4	Same qty in both versions High-torque servos for the most loaded leg joints.	ROBOTIS: $310.39
DYNAMIXEL XM430-W350-T leg servos (2XM version only)	1	0 in 2XC, 4 in the 2XM version Stronger option for the 2XM build.	ROBOTIS: $310.39
DYNAMIXEL HN11-I101 set servo horns	10	2XC qty 10; 2XM qty 8 Idler and drive horns for the 430-series servos.	ROBOTIS: $8.05
DYNAMIXEL HN12-I101 set servo horns	4	2XC qty 4; 2XM qty 6 Horns for the XC330 servos.	ROBOTIS: $20.47
NVIDIA Jetson Orin NX 16GB (Seeed reComputer J4012) onboard computer	1	BOM lists $955; Jetson Orin Nano is the budget swap Runs policies, cameras and teleop onboard.	Seeed Studio: $1,399.00
AW-CB375NF M.2 WiFi card wireless	1	BOM lists $18.36 Adds WiFi and Bluetooth to the Jetson.	Amazon: check price
WiFi antenna, IPX MHF4 wireless	1	BOM lists $9.49 Antennas for the WiFi card.	Amazon: check price
Arducam 1080P fisheye USB camera (IMX291, 160 degree) cameras	2	BOM lists $49.99 each Stereo eyes for teleop, depth and policy input.	Amazon: check price
Adafruit BNO085 9-DOF IMU breakout (ID 4754) IMU	1	BOM lists $24.95 Body orientation for balance policies.	Adafruit: $29.50
Phone replacement speaker (MMOBIEL, iPhone SE) audio	1	BOM lists $5.99 Small speaker that fits the head.	Amazon: check price
HiLetgo M38 Bluetooth audio receiver board, 3 pcs audio	1	BOM lists $7.99 Drives the speaker.	Amazon: check price
Pololu 12V 4.5A step-down regulator D36V50F12 power regulation	2	BOM lists $34.95 Steady 12V rails from the battery.	Pololu: $39.95
ToddlerBot TTL power board V8 (custom PCB) power distribution	1	Gerbers and BOM in the docs; order assembled from JLCPCB; not in the main BOM Splits power and the servo TTL bus to six chains.	no verified seller yet
2000 mAh LiPo battery battery	1	BOM lists $49.99 Untethered power.	Amazon: check price
LiPo voltage tester battery care	1	BOM lists $12.95 The docs stress watching voltage to avoid over-discharge.	Amazon: check price
LiPo balance charger battery care	1	BOM lists $31.99 Charges the pack safely.	Amazon: check price
XT30 male/female plugs, 5 pairs connectors	1	BOM lists $9.99 Battery and power leads.	Amazon: check price
XT30 to XT60 adapters, 4 pcs connectors	1	BOM lists $8.99 Connects bench supply or charger leads.	Amazon: check price
5.5 x 2.5 mm barrel jack connector connectors	1	BOM lists $9.49 Jetson power input.	Amazon: check price
Rocker switch, 5 pcs switches	1	BOM lists $5.99 Main power switch.	Amazon: check price
JST EH 3-pin cables and housings wiring	1	BOM: 10 cables ($0.38 each) and 25 housings from DigiKey (shortened links) Servo bus wiring between chains.	no verified seller yet
14 AWG power extension cable wiring	1	BOM lists $17.49 Main power wiring.	Amazon: check price
USB to micro USB cables (0.5 ft and 1.5 ft) and a USB hub splitter cables	1	BOM: B0CGRG7F2Q, B0773N757H, hub B088KBGRD9 Connects the board, cameras and IMU to the Jetson.	Amazon: check price
683-2RS bearings 3x7x3 mm, 10-pack bearings	1	BOM lists $11.96 Joint support bearings.	Amazon: check price
684ZZ bearings 4x9x4 mm, 10-pack bearings	2	BOM lists $7.99 per pack Joint support bearings.	Amazon: check price
AXK0414 thrust needle bearing bearings	30	BOM lists $1.48 each (AliExpress; Amazon alternative) Takes axial load in printed joints.	AliExpress: check price (unverified) BOM link Amazon: check price
Oilless sleeve bushings 3x5x5 mm, 10 pcs bushings	1	BOM lists $5.99 Plain bearings for sliding parts.	Amazon: check price
5 mm rubber tape feet	1	BOM lists $16.99 Grip on the foot soles.	Amazon: check price
Screw kits: M2 (x2), M2.5, M3 flat head, M4, M4 long; M3x8 and M3x10 set screws; M3/M4 lock nuts fasteners	1	BOM lists these as eight Amazon kits, about $93 total; pre-coated M2x6 screws from Taobao are recommended Everything bolts to printed parts and servo horns.	Amazon: check price Amazon: check price Amazon: check price
Vibra-TITE 213 threadlocker	1	BOM lists $6.55 Keeps servo-horn screws from backing out.	Amazon: check price
Bambu PLA-CF 1 kg filament	2	BOM lists $34.99 Stiffer parts and the waist gears (docs say PLA-CF lasts longer there).	Bambu Lab: $34.99 1 kg
Bambu PLA Basic 1 kg filament	1	BOM lists $19.99 Remaining printed parts.	Bambu Lab: $14.99 1 kg; lowest variant shown

Quantities follow the official ToddlerBot 2.0 docs: https://hshi74.github.io/toddlerbot. "Unverified" prices come from search listings or older BOMs that we could not confirm on the seller's product page.

Kits (fewer orders, check what they leave out)

Kit	Price	Includes	Leaves out	Buy
ToddlerBot 2.0 fully assembled WowRobo	$4,299.00	Assembled robot per the official BOM's kit row	Jetson Orin NX, WiFi card and battery per the BOM note; the ToddlerBot team says it is not affiliated and has not tested it	WowRobo: $4,299.00

3D printed parts

Needed. Bambu printers recommended; MakerWorld has ready 3MF plates with orientation and profiles. PLA-CF with extra wall loops for the waist gears. CAD on Onshape for edits. Files: https://makerworld.com/en/models/1733983

Mistakes builders make

Pick 2XC (default) or 2XM before buying; the servo list differs (2XM swaps the 2XL430s for 2XC430s and adds four XM430-W350s).
Onshape shows 2XL430 where the BOM says 2XC430; the maintainer says the BOM is right but 2XL works on a tight budget (issue #8).
Run all servos at 2 Mbps; the XC330s throw 'no status packet' warnings at 4 Mbps.
Watch battery voltage with the tester; low voltage both damages the LiPo and weakens high-torque moves.
Intermittent servo dropouts are usually a loose cable; the team traced one to a wire near the ankle.
Waist gears wear over time; reprint them in PLA-CF with more walls.
The custom power PCB is not in the BOM; order it assembled from JLCPCB using the docs' files.
Jetson Orin NX now costs about $1,399 at Seeed, well above the $955 in the BOM.

FAQ

How much does it cost to build the ToddlerBot 2.0?

About $5,730 to $7,760 in parts at current prices, Low end is the official BOM essentials total for the recommended 2XC version ($5,727.94); high end is the stronger 2XM version ($7,293.56) plus today's higher Jetson price ($1,399 vs $955 in the BOM). Excludes the custom power PCB (JLCPCB), tools (about $1,976 in the BOM, mostly a Bambu printer and soldering kit) and the optional teleop arms..

Do I need a 3D printer for the ToddlerBot 2.0?

Yes. Bambu printers recommended; MakerWorld has ready 3MF plates with orientation and profiles. PLA-CF with extra wall loops for the waist gears. CAD on Onshape for edits.